New template added for Inline Form Errors summary

The inline_form_errors module now ships with a template core/modules/inline_form_errors/templates/inline-form-errors-summary.html.twig

{% if error_links %}
  {%- set count = error_links|length -%}
  {%- trans -%}
    <span>{{ count }} error has been found:</span>
  {%- plural count -%}
    <span>{{ count }} errors have been found:</span>
  {%- endtrans -%}
  {{ include('item-list.html.twig', {
    items: error_links,
    list_type: 'ul',
    wrapper_attributes: create_attribute(),
    context: {list_style: 'comma-list'},
  }) }}
{% endif %}

Which is used to display the summary of errors.

In addition there are theme suggestions based on the $form_id. $suggestions[] = 'inline_form_errors_summary__' . $variables['form_id'];